/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsMathMLChar_h___

#define nsMathMLChar_h___

#include "nsColor.h"

#include "nsMathMLOperators.h"

#include "nsPoint.h"

#include "nsRect.h"

#include "nsString.h"

#include "nsBoundingMetrics.h"

#include "gfxTextRun.h"

class gfxContext;

class nsGlyphTable;

class nsIFrame;

class nsDisplayListBuilder;

class nsDisplayListSet;

class nsPresContext;

struct nsBoundingMetrics;

struct nsFont;

namespace mozilla {

class ComputedStyle;

}

// Hints for Stretch() to indicate criteria for stretching

enum {

  // Don't stretch

  NS_STRETCH_NONE     = 0x00,

  // Variable size stretches

  NS_STRETCH_VARIABLE_MASK = 0x0F,

  NS_STRETCH_NORMAL   = 0x01, // try to stretch to requested size

  NS_STRETCH_NEARER   = 0x02, // stretch very close to requested size

  NS_STRETCH_SMALLER  = 0x04, // don't stretch more than requested size

  NS_STRETCH_LARGER   = 0x08, // don't stretch less than requested size

  // A largeop in displaystyle

  NS_STRETCH_LARGEOP  = 0x10,

  NS_STRETCH_INTEGRAL  = 0x20,

  // Intended for internal use:

  // Find the widest metrics that might be returned from a vertical stretch

  NS_STRETCH_MAXWIDTH = 0x40

};

// A single glyph in our internal representation is either

// 1) a 'code@font' pair from the mathfontFONTFAMILY.properties table. The

// 'code' is interpreted as a Unicode point. The 'font' is a numeric

// identifier given to the font to which the glyph belongs, which is 0 for the

// FONTFAMILY and > 0 for 'external' fonts.

// 2) a glyph index from the Open Type MATH table. In that case, all the glyphs

// come from the font containing that table and 'font' is just set to -1.

struct nsGlyphCode {

  union {

    char16_t code[2];

    uint32_t glyphID;

  };

  int8_t   font;

  bool IsGlyphID() const { return font == -1; }

  int32_t Length() const {

    return (IsGlyphID() || code[1] == char16_t('\0') ? 1 : 2);

  }

  bool Exists() const

  {

    return IsGlyphID() ? glyphID != 0 : code[0] != 0;

  }

  bool operator==(const nsGlyphCode& other) const

  {

    return (other.font == font &&

            ((IsGlyphID() && other.glyphID == glyphID) ||

             (!IsGlyphID() && other.code[0] == code[0] &&

              other.code[1] == code[1])));

  }

  bool operator!=(const nsGlyphCode& other) const

  {

    return ! operator==(other);

  }

};

// Class used to handle stretchy symbols (accent, delimiter and boundary

// symbols).

class nsMathMLChar

{

public:

  typedef gfxTextRun::Range Range;

  typedef mozilla::gfx::DrawTarget DrawTarget;

  // constructor and destructor

  nsMathMLChar()

    : mDirection(NS_STRETCH_DIRECTION_DEFAULT)

  {

    MOZ_COUNT_CTOR(nsMathMLChar);

    mComputedStyle = nullptr;

    mUnscaledAscent = 0;

    mScaleX = mScaleY = 1.0;

    mDraw = DRAW_NORMAL;

    mMirrored = false;

  }

  // not a virtual destructor: this class is not intended to be subclassed

  ~nsMathMLChar();

  void Display(nsDisplayListBuilder*   aBuilder,

               nsIFrame*               aForFrame,

               const nsDisplayListSet& aLists,

               uint32_t                aIndex,

               const nsRect*           aSelectedRect = nullptr);

  void PaintForeground(nsIFrame* aForFrame,

                       gfxContext& aRenderingContext,

                       nsPoint aPt,

                       bool aIsSelected);

  // This is the method called to ask the char to stretch itself.

  // @param aContainerSize - IN - suggested size for the stretched char

  // @param aDesiredStretchSize - OUT - the size that the char wants

  nsresult

  Stretch(nsIFrame*                aForFrame,

          DrawTarget*              aDrawTarget,

          float                    aFontSizeInflation,

          nsStretchDirection       aStretchDirection,

          const nsBoundingMetrics& aContainerSize,

          nsBoundingMetrics&       aDesiredStretchSize,

          uint32_t                 aStretchHint,

          bool                     aRTL);

  void

  SetData(nsString& aData);

  void

  GetData(nsString& aData) {

    aData = mData;

  }

  int32_t

  Length() {

    return mData.Length();

  }

  nsStretchDirection

  GetStretchDirection() {

    return mDirection;

  }

  // Sometimes we only want to pass the data to another routine,

  // this function helps to avoid copying

  const char16_t*

  get() {

    return mData.get();

  }

  void

  GetRect(nsRect& aRect) {

    aRect = mRect;

  }

  void

  SetRect(const nsRect& aRect) {

    mRect = aRect;

  }

  // Get the maximum width that the character might have after a vertical

  // Stretch().

  //

  // @param aStretchHint can be the value that will be passed to Stretch().

  // It is used to determine whether the operator is stretchy or a largeop.

  nscoord

  GetMaxWidth(nsIFrame* aForFrame,

              DrawTarget* aDrawTarget,

              float aFontSizeInflation,

              uint32_t aStretchHint = NS_STRETCH_NORMAL);

  // Metrics that _exactly_ enclose the char. The char *must* have *already*

  // being stretched before you can call the GetBoundingMetrics() method.

  // IMPORTANT: since chars have their own ComputedStyles, and may be rendered

  // with glyphs that are not in the parent font, just calling the default

  // aRenderingContext.GetBoundingMetrics(aChar) can give incorrect results.

  void

  GetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {

    aBoundingMetrics = mBoundingMetrics;

  }

  void

  SetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {

    mBoundingMetrics = aBoundingMetrics;

  }

  // Hooks to access the extra leaf ComputedStyles given to the MathMLChars.

  // They provide an interface to make them accessible to the Style System via

  // the Get/Set AdditionalComputedStyle() APIs. Owners of MathMLChars

  // should honor these APIs.

  mozilla::ComputedStyle* GetComputedStyle() const;

  void SetComputedStyle(mozilla::ComputedStyle* aComputedStyle);

protected:

  friend class nsGlyphTable;

  friend class nsPropertiesTable;

  friend class nsOpenTypeTable;

  nsString           mData;

private:

  nsRect             mRect;

  nsStretchDirection mDirection;

  nsBoundingMetrics  mBoundingMetrics;

  RefPtr<mozilla::ComputedStyle> mComputedStyle;

  // mGlyphs/mBmData are arrays describing the glyphs used to draw the operator.

  // See the drawing methods below.

  RefPtr<gfxTextRun> mGlyphs[4];

  nsBoundingMetrics     mBmData[4];

  // mUnscaledAscent is the actual ascent of the char.

  nscoord            mUnscaledAscent;

  // mScaleX, mScaleY are the factors by which we scale the char.

  float              mScaleX, mScaleY;

  // mDraw indicates how we draw the stretchy operator:

  // - DRAW_NORMAL: we render the mData string normally.

  // - DRAW_VARIANT: we draw a larger size variant given by mGlyphs[0].

  // - DRAW_PARTS: we assemble several parts given by mGlyphs[0], ... mGlyphs[4]

  // XXXfredw: the MATH table can have any numbers of parts and extenders.

  enum DrawingMethod {

    DRAW_NORMAL, DRAW_VARIANT, DRAW_PARTS

  };

  DrawingMethod mDraw;

  // mMirrored indicates whether the character is mirrored.

  bool               mMirrored;

  class StretchEnumContext;

  friend class StretchEnumContext;

  // helper methods

  bool

  SetFontFamily(nsPresContext*          aPresContext,

                const nsGlyphTable*     aGlyphTable,

                const nsGlyphCode&      aGlyphCode,

                const mozilla::FontFamilyList& aDefaultFamily,

                nsFont&                 aFont,

                RefPtr<gfxFontGroup>* aFontGroup);

  nsresult

  StretchInternal(nsIFrame*                aForFrame,

                  DrawTarget*              aDrawTarget,

                  float                    aFontSizeInflation,

                  nsStretchDirection&      aStretchDirection,

                  const nsBoundingMetrics& aContainerSize,

                  nsBoundingMetrics&       aDesiredStretchSize,

                  uint32_t                 aStretchHint,

                  float           aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY,

                  bool            aMaxSizeIsAbsolute = false);

  nsresult

  PaintVertically(nsPresContext* aPresContext,

                  gfxContext*    aThebesContext,

                  nsRect&        aRect,

                  nscolor        aColor);

  nsresult

  PaintHorizontally(nsPresContext* aPresContext,

                    gfxContext*    aThebesContext,

                    nsRect&        aRect,

                    nscolor        aColor);

  void

  ApplyTransforms(gfxContext* aThebesContext, int32_t aAppUnitsPerGfxUnit,

                  nsRect &r);

};

#endif /* nsMathMLChar_h___ */